We just use the normal Gmail client user interface. We’ve trialled different ‘front-ends’ but keep coming back to Gmail primarily due to the add-ons and extensions that can be built in (e.g. into Trello, Slack, Loom etc).

The best way of communicating with clients for calls. It can be used both for video and teleconference calls. So much more reliable than Skype. Nice integrations with Google Calendar to set up Zoom meetings directly via calendar invitations too.